Unlimited File Size

While the Compress API is built to handle very large images, it’s possible that you’ll run into some limits in certain scenarios:

All images: API uploads are currently capped to 150MB, just to ensure some joker doesn’t try and abuse the system. There is also a time limit of 5 minutes on all optimizations/conversions (I’ve yet to find an image that even comes close to 5 minutes).
JPG: The largest JPG image tested to date is 94MB. The largest JPG image in the world is nearly a terabyte (stitched together from thousands of smaller photos), and there’s no way we could process that image, but anything your camera can produce, we can optimize.
PNG: Images in the PNG format are not very large in general, but depending on your server configuration, you could easily run into timeouts on your website with PNG images over 500kb. I’ve tested images up to 8 MB without any problems, but sometimes a 300kb image will take a minute or two to process.
GIF: We've processed GIF images over 80MB, it might take a while, but we can generally handle them if your server doesn't timeout first.
PDF: We regularly optimize PDF files over 100MB.
WebP: The format itself is limited to 16,383 x 16,383 (in pixels), so any PNG or JPG that fits within those dimensions can be converted.